While sudden death is common because of the huge voltage of a lightning strike, survivors often fare better than victims of other electrical injuries caused by a more prolonged application of lesser voltage.[1]

Ground strike near the person causing a difference of potential in the ground itself (due to resistance to current in the Earth), amounting to several thousand volts per foot, depending upon the composition of the earth that makes up the ground at that location (sand being a fair insulator and wet, salty and spongy earth being more conductive).

EMP or electromagnetic pulse from close strikes – especially during positive lightning discharges

In a direct hit, the electrical charge strikes the person first.
Splash hits occur when lightning jumps to a person (lower resistance path) from a nearby object that has more resistance, striking the person on its way to the ground.
In ground strikes, the bolt lands near the person and is conducted by a connection to the ground (usually the feet), due to the voltage gradient in the earth. This can still cause substantial injury.

Counterintuitively, lightning current flowing through the victim's body resistance may develop a high voltage sufficient to flash around the skin or clothing to the ground in a direct strike, resulting in a surprisingly benign outcome.

The lightning often leaves skin burns in characteristic Lichtenberg figures, sometimes called lightning flowers; they may persist for hours or days, and are a useful indicator for medical examiners when trying to determine the cause of death. They are thought to be caused by the rupture of small capillaries under the skin, either from the lightning current or from the mechanical shock wave. The intense electric current can cause a loss of consciousness; it is also speculated that the EMP created by a nearby lightning strike can cause cardiac arrest.

A bolt of lightning can reach temperatures approaching 28,000° Celsius (50,000° Fahrenheit) in a split second. This is about five times hotter than the surface of the sun.[4] Spectacular and unconventional lightning damage can be caused by thermal effects of lightning. Hot lightning (high-current lightning) which lasts for more than a second can deposit immense energy, melting or carbonizing large objects. One such example is the destruction of the basement insulator of the 250 m (820 ft) high central mast of the Orlunda radio transmitter, which led to its collapse. The intense heat generated by a lightning strike can burn tissue, and cause lung damage, and the chest can be damaged by the mechanical force of rapidly expanding heated air.

Just as heat can cause expanding air in the lungs, the explosive shock wave created by lightning (the cause of thunder) can cause concussive and auditory injury at extremely close range. Other physical injury can be caused by objects damaged or thrown by the lightning strike. For example, lightning striking a nearby tree may vaporize sap, and the steam explosion often causes bark and wood fragments to be explosively ejected.

Reported mortality rates range from 10–30 percent, depending on the source of data. Most people who are struck by lightning live to tell the story, but many suffer from long term injury or disability.[5]

Experiments on sheep show that a lightning strike to the head of a victim enters through the eyes, ears, nose and mouth, converging at the brainstem, which controls breathing. Many unconscious victims, who appear lifeless, actually die of suffocation[citation needed]. Chances of survival may be increased if cardiopulmonary resuscitation (CPR) is started immediately, and continued without interruption until the brainstem recovers.[7]